#include "nest/route.h"
#include "nest/protocol.h"
#include "nest/iface.h"
-#include "lib/alloca.h"
#include "lib/timer.h"
#include "lib/unix.h"
#include "lib/krt.h"
#endif
+#ifdef IPV6
+#define krt_ecmp6(X) 1
+#else
+#define krt_ecmp6(X) 0
+#endif
+
+/*
+ * Structure nl_parse_state keeps state of received route processing. Ideally,
+ * we could just independently parse received Netlink messages and immediately
+ * propagate received routes to the rest of BIRD, but Linux kernel represents
+ * and announces IPv6 ECMP routes not as one route with multiple next hops (like
+ * RTA_MULTIPATH in IPv4 ECMP), but as a set of routes with the same prefix.
+ *
+ * Therefore, BIRD keeps currently processed route in nl_parse_state structure
+ * and postpones its propagation until we expect it to be final; i.e., when
+ * non-matching route is received or when the scan ends. When another matching
+ * route is received, it is merged with the already processed route to form an
+ * ECMP route. Note that merging is done only for IPv6 (merge == 1), but the
+ * postponing is done in both cases (for simplicity). All IPv4 routes are just
+ * considered non-matching.
+ *
+ * This is ignored for asynchronous notifications (every notification is handled
+ * as a separate route). It is not an issue for our routes, as we ignore such
+ * notifications anyways. But importing alien IPv6 ECMP routes does not work
+ * properly.
+ */
+
+struct nl_parse_state
+{
+ struct linpool *pool;
+ int scan;
+ int merge;
+
+ net *net;
+ rta *attrs;
+ struct krt_proto *proto;
+ s8 new;
+ s8 krt_src;
+ u8 krt_type;
+ u8 krt_proto;
+ u32 krt_metric;
+};
+
/*
* Synchronous Netlink interface
*/
#define NL_RX_SIZE 8192
+#define NL_OP_DELETE 0
+#define NL_OP_ADD (NLM_F_CREATE|NLM_F_EXCL)
+#define NL_OP_REPLACE (NLM_F_CREATE|NLM_F_REPLACE)
+#define NL_OP_APPEND (NLM_F_CREATE|NLM_F_APPEND)
+
+static linpool *nl_linpool;
+
static struct nl_sock nl_scan = {.fd = -1}; /* Netlink socket for synchronous scan */
static struct nl_sock nl_req = {.fd = -1}; /* Netlink socket for requests */
static struct tbf rl_netlink_err = TBF_DEFAULT_LOG_LIMITS;
static int
-nl_error(struct nlmsghdr *h)
+nl_error(struct nlmsghdr *h, int ignore_esrch)
{
struct nlmsgerr *e;
int ec;
}
e = (struct nlmsgerr *) NLMSG_DATA(h);
ec = -e->error;
- if (ec)
+ if (ec && !(ignore_esrch && (ec == ESRCH)))
log_rl(&rl_netlink_err, L_WARN "Netlink: %s", strerror(ec));
return ec;
}
return NULL;
if (h->nlmsg_type == NLMSG_ERROR)
{
- nl_error(h);
+ nl_error(h, 0);
return NULL;
}
return h;
}
static int
-nl_exchange(struct nlmsghdr *pkt)
+nl_exchange(struct nlmsghdr *pkt, int ignore_esrch)
{
struct nlmsghdr *h;
break;
log(L_WARN "nl_exchange: Unexpected reply received");
}
- return nl_error(h) ? -1 : 0;
+ return nl_error(h, ignore_esrch) ? -1 : 0;
}
/*
}
static int
-nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int new)
+nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int op, int dest, ip_addr gw, struct iface *iface)
{
eattr *ea;
net *net = e->net;
char buf[128 + KRT_METRICS_MAX*8 + nh_bufsize(a->nexthops)];
} r;
- DBG("nl_send_route(%I/%d,new=%d)\n", net->n.prefix, net->n.pxlen, new);
+ DBG("nl_send_route(%I/%d,op=%x)\n", net->n.prefix, net->n.pxlen, op);
bzero(&r.h, sizeof(r.h));
bzero(&r.r, sizeof(r.r));
- r.h.nlmsg_type = new ? RTM_NEWROUTE : RTM_DELROUTE;
+ r.h.nlmsg_type = op ? RTM_NEWROUTE : RTM_DELROUTE;
r.h.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
- r.h.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | (new ? NLM_F_CREATE|NLM_F_EXCL : 0);
+ r.h.nlmsg_flags = op | NLM_F_REQUEST | NLM_F_ACK;
r.r.rtm_family = BIRD_AF;
r.r.rtm_dst_len = net->n.pxlen;
r.r.rtm_scope = RT_SCOPE_UNIVERSE;
nl_add_attr_ipa(&r.h, sizeof(r), RTA_DST, net->n.prefix);
+ /*
+ * Strange behavior for RTM_DELROUTE:
+ * 1) rtm_family is ignored in IPv6, works for IPv4
+ * 2) not setting RTA_PRIORITY is different from setting default value (on IPv6)
+ * 3) not setting RTA_PRIORITY is equivalent to setting 0, which is wildcard
+ */
+
if (krt_table_id(p) < 256)
r.r.rtm_table = krt_table_id(p);
else
nl_add_attr_u32(&r.h, sizeof(r), RTA_TABLE, krt_table_id(p));
- /* For route delete, we do not specify route attributes */
- if (!new)
- return nl_exchange(&r.h);
-
+ /* For route delete, we do not specify remaining route attributes */
+ if (op == NL_OP_DELETE)
+ goto dest;
if (ea = ea_find(eattrs, EA_KRT_METRIC))
nl_add_attr_u32(&r.h, sizeof(r), RTA_PRIORITY, ea->u.data);
nl_add_metrics(&r.h, sizeof(r), metrics, KRT_METRICS_MAX);
+dest:
/* a->iface != NULL checked in krt_capable() for router and device routes */
-
- switch (a->dest)
+ switch (dest)
{
case RTD_ROUTER:
r.r.rtm_type = RTN_UNICAST;
- nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, a->iface->index);
- nl_add_attr_ipa(&r.h, sizeof(r), RTA_GATEWAY, a->gw);
+ nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, iface->index);
+ nl_add_attr_ipa(&r.h, sizeof(r), RTA_GATEWAY, gw);
break;
case RTD_DEVICE:
r.r.rtm_type = RTN_UNICAST;
- nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, a->iface->index);
+ nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, iface->index);
break;
case RTD_BLACKHOLE:
r.r.rtm_type = RTN_BLACKHOLE;
r.r.rtm_type = RTN_UNICAST;
nl_add_multipath(&r.h, sizeof(r), a->nexthops);
break;
+ case RTD_NONE:
+ break;
default:
bug("krt_capable inconsistent with nl_send_route");
}
- return nl_exchange(&r.h);
+ /* Ignore missing for DELETE */
+ return nl_exchange(&r.h, (op == NL_OP_DELETE));
+}
+
+static inline int
+nl_add_rte(struct krt_proto *p, rte *e, struct ea_list *eattrs)
+{
+ rta *a = e->attrs;
+ int err = 0;
+
+ if (krt_ecmp6(p) && (a->dest == RTD_MULTIPATH))
+ {
+ struct mpnh *nh = a->nexthops;
+
+ err = nl_send_route(p, e, eattrs, NL_OP_ADD, RTD_ROUTER, nh->gw, nh->iface);
+ if (err < 0)
+ return err;
+
+ for (nh = nh->next; nh; nh = nh->next)
+ err += nl_send_route(p, e, eattrs, NL_OP_APPEND, RTD_ROUTER, nh->gw, nh->iface);
+
+ return err;
+ }
+
+ return nl_send_route(p, e, eattrs, NL_OP_ADD, a->dest, a->gw, a->iface);
+}
+
+static inline int
+nl_delete_rte(struct krt_proto *p, rte *e, struct ea_list *eattrs)
+{
+ int err = 0;
+
+ /* For IPv6, we just repeatedly request DELETE until we get error */
+ do
+ err = nl_send_route(p, e, eattrs, NL_OP_DELETE, RTD_NONE, IPA_NONE, NULL);
+ while (krt_ecmp6(p) && !err);
+
+ return err;
}
void
int err = 0;
/*
- * NULL for eattr of the old route is a little hack, but we don't
- * get proper eattrs for old in rt_notify() anyway. NULL means no
- * extended route attributes and therefore matches if the kernel
- * route has any of them.
+ * We could use NL_OP_REPLACE, but route replace on Linux has some problems:
+ *
+ * 1) Does not check for matching rtm_protocol
+ * 2) Has broken semantics for IPv6 ECMP
+ * 3) Crashes some kernel version when used for IPv6 ECMP
+ *
+ * So we use NL_OP_DELETE and then NL_OP_ADD. We also do not trust the old
+ * route value, so we do not try to optimize IPv6 ECMP reconfigurations.
*/
if (old)
- nl_send_route(p, old, NULL, 0);
+ nl_delete_rte(p, old, eattrs);
if (new)
- err = nl_send_route(p, new, eattrs, 1);
+ err = nl_add_rte(p, new, eattrs);
if (err < 0)
n->n.flags |= KRF_SYNC_ERROR;
}
+static inline struct mpnh *
+nl_alloc_mpnh(struct nl_parse_state *s, ip_addr gw, struct iface *iface, byte weight)
+{
+ struct mpnh *nh = lp_alloc(s->pool, sizeof(struct mpnh));
+
+ nh->gw = gw;
+ nh->iface = iface;
+ nh->next = NULL;
+ nh->weight = weight;
+
+ return nh;
+}
+
+static int
+nl_mergable_route(struct nl_parse_state *s, net *net, struct krt_proto *p, uint priority, uint krt_type)
+{
+ /* Route merging must be active */
+ if (!s->merge)
+ return 0;
+
+ /* Saved and new route must have same network, proto/table, and priority */
+ if ((s->net != net) || (s->proto != p) || (s->krt_metric != priority))
+ return 0;
+
+ /* Both must be regular unicast routes */
+ if ((s->krt_type != RTN_UNICAST) || (krt_type != RTN_UNICAST))
+ return 0;
+
+ return 1;
+}
+
+static void
+nl_announce_route(struct nl_parse_state *s)
+{
+ rte *e = rte_get_temp(s->attrs);
+ e->net = s->net;
+ e->u.krt.src = s->krt_src;
+ e->u.krt.proto = s->krt_proto;
+ e->u.krt.seen = 0;
+ e->u.krt.best = 0;
+ e->u.krt.metric = s->krt_metric;
+
+ if (s->scan)
+ krt_got_route(s->proto, e);
+ else
+ krt_got_route_async(s->proto, e, s->new);
+
+ s->net = NULL;
+ s->attrs = NULL;
+ s->proto = NULL;
+ lp_flush(s->pool);
+}
+
+static inline void
+nl_parse_begin(struct nl_parse_state *s, int scan, int merge)
+{
+ memset(s, 0, sizeof (struct nl_parse_state));
+ s->pool = nl_linpool;
+ s->scan = scan;
+ s->merge = merge;
+}
+
+static inline void
+nl_parse_end(struct nl_parse_state *s)
+{
+ if (s->net)
+ nl_announce_route(s);
+}
+
+
#define SKIP(ARG...) do { DBG("KRT: Ignoring route - " ARG); return; } while(0)
static void
-nl_parse_route(struct nlmsghdr *h, int scan)
+nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
{
struct krt_proto *p;
struct rtmsg *i;
ip_addr dst = IPA_NONE;
u32 oif = ~0;
u32 table;
+ u32 priority = 0;
int src;
if (!(i = nl_checkin(h, sizeof(*i))))
if (!p)
SKIP("unknown table %d\n", table);
-
#ifdef IPV6
if (a[RTA_IIF])
SKIP("IIF set\n");
SKIP("TOS %02x\n", i->rtm_tos);
#endif
- if (scan && !new)
+ if (s->scan && !new)
SKIP("RTM_DELROUTE in scan\n");
+ if (a[RTA_PRIORITY])
+ priority = rta_get_u32(a[RTA_PRIORITY]);
+
int c = ipa_classify_net(dst);
if ((c < 0) || !(c & IADDR_HOST) || ((c & IADDR_SCOPE_MASK) <= SCOPE_LINK))
SKIP("strange class/scope\n");
// if (i->rtm_scope != RT_SCOPE_UNIVERSE)
// SKIP("scope %u\n", i->rtm_scope);
+
switch (i->rtm_protocol)
{
case RTPROT_UNSPEC:
return;
case RTPROT_BIRD:
- if (!scan)
+ if (!s->scan)
SKIP("echo\n");
src = KRT_SRC_BIRD;
break;
net *net = net_get(p->p.table, dst, i->rtm_dst_len);
- rta ra = {
- .src= p->p.main_source,
- .source = RTS_INHERIT,
- .scope = SCOPE_UNIVERSE,
- .cast = RTC_UNICAST
- };
+ if (s->net && !nl_mergable_route(s, net, p, priority, i->rtm_type))
+ nl_announce_route(s);
+
+ rta *ra = lp_allocz(s->pool, sizeof(rta));
+ ra->src = p->p.main_source;
+ ra->source = RTS_INHERIT;
+ ra->scope = SCOPE_UNIVERSE;
+ ra->cast = RTC_UNICAST;
switch (i->rtm_type)
{
if (a[RTA_MULTIPATH] && (i->rtm_family == AF_INET))
{
- ra.dest = RTD_MULTIPATH;
- ra.nexthops = nl_parse_multipath(p, a[RTA_MULTIPATH]);
- if (!ra.nexthops)
+ ra->dest = RTD_MULTIPATH;
+ ra->nexthops = nl_parse_multipath(p, a[RTA_MULTIPATH]);
+ if (!ra->nexthops)
{
log(L_ERR "KRT: Received strange multipath route %I/%d",
net->n.prefix, net->n.pxlen);
break;
}
- ra.iface = if_find_by_index(oif);
- if (!ra.iface)
+ ra->iface = if_find_by_index(oif);
+ if (!ra->iface)
{
log(L_ERR "KRT: Received route %I/%d with unknown ifindex %u",
net->n.prefix, net->n.pxlen, oif);
if (a[RTA_GATEWAY])
{
neighbor *ng;
- ra.dest = RTD_ROUTER;
- memcpy(&ra.gw, RTA_DATA(a[RTA_GATEWAY]), sizeof(ra.gw));
- ipa_ntoh(ra.gw);
+ ra->dest = RTD_ROUTER;
+ memcpy(&ra->gw, RTA_DATA(a[RTA_GATEWAY]), sizeof(ra->gw));
+ ipa_ntoh(ra->gw);
#ifdef IPV6
/* Silently skip strange 6to4 routes */
- if (ipa_in_net(ra.gw, IPA_NONE, 96))
+ if (ipa_in_net(ra->gw, IPA_NONE, 96))
return;
#endif
- ng = neigh_find2(&p->p, &ra.gw, ra.iface,
+ ng = neigh_find2(&p->p, &ra->gw, ra->iface,
(i->rtm_flags & RTNH_F_ONLINK) ? NEF_ONLINK : 0);
if (!ng || (ng->scope == SCOPE_HOST))
{
log(L_ERR "KRT: Received route %I/%d with strange next-hop %I",
- net->n.prefix, net->n.pxlen, ra.gw);
+ net->n.prefix, net->n.pxlen, ra->gw);
return;
}
}
else
{
- ra.dest = RTD_DEVICE;
+ ra->dest = RTD_DEVICE;
}
break;
case RTN_BLACKHOLE:
- ra.dest = RTD_BLACKHOLE;
+ ra->dest = RTD_BLACKHOLE;
break;
case RTN_UNREACHABLE:
- ra.dest = RTD_UNREACHABLE;
+ ra->dest = RTD_UNREACHABLE;
break;
case RTN_PROHIBIT:
- ra.dest = RTD_PROHIBIT;
+ ra->dest = RTD_PROHIBIT;
break;
/* FIXME: What about RTN_THROW? */
default:
return;
}
- rte *e = rte_get_temp(&ra);
- e->net = net;
- e->u.krt.src = src;
- e->u.krt.proto = i->rtm_protocol;
- e->u.krt.seen = 0;
- e->u.krt.best = 0;
- e->u.krt.metric = 0;
-
- if (a[RTA_PRIORITY])
- e->u.krt.metric = rta_get_u32(a[RTA_PRIORITY]);
-
if (a[RTA_PREFSRC])
{
ip_addr ps;
memcpy(&ps, RTA_DATA(a[RTA_PREFSRC]), sizeof(ps));
ipa_ntoh(ps);
- ea_list *ea = alloca(sizeof(ea_list) + sizeof(eattr));
- ea->next = ra.eattrs;
- ra.eattrs = ea;
+ ea_list *ea = lp_alloc(s->pool, sizeof(ea_list) + sizeof(eattr));
+ ea->next = ra->eattrs;
+ ra->eattrs = ea;
ea->flags = EALF_SORTED;
ea->count = 1;
ea->attrs[0].id = EA_KRT_PREFSRC;
ea->attrs[0].flags = 0;
ea->attrs[0].type = EAF_TYPE_IP_ADDRESS;
- ea->attrs[0].u.ptr = alloca(sizeof(struct adata) + sizeof(ps));
+ ea->attrs[0].u.ptr = lp_alloc(s->pool, sizeof(struct adata) + sizeof(ps));
ea->attrs[0].u.ptr->length = sizeof(ps);
memcpy(ea->attrs[0].u.ptr->data, &ps, sizeof(ps));
}
if (a[RTA_FLOW])
{
- ea_list *ea = alloca(sizeof(ea_list) + sizeof(eattr));
- ea->next = ra.eattrs;
- ra.eattrs = ea;
+ ea_list *ea = lp_alloc(s->pool, sizeof(ea_list) + sizeof(eattr));
+ ea->next = ra->eattrs;
+ ra->eattrs = ea;
ea->flags = EALF_SORTED;
ea->count = 1;
ea->attrs[0].id = EA_KRT_REALM;
if (a[RTA_METRICS])
{
u32 metrics[KRT_METRICS_MAX];
- ea_list *ea = alloca(sizeof(ea_list) + KRT_METRICS_MAX * sizeof(eattr));
+ ea_list *ea = lp_alloc(s->pool, sizeof(ea_list) + KRT_METRICS_MAX * sizeof(eattr));
int t, n = 0;
if (nl_parse_metrics(a[RTA_METRICS], metrics, ARRAY_SIZE(metrics)) < 0)
if (n > 0)
{
- ea->next = ra.eattrs;
+ ea->next = ra->eattrs;
ea->flags = EALF_SORTED;
ea->count = n;
- ra.eattrs = ea;
+ ra->eattrs = ea;
}
}
- if (scan)
- krt_got_route(p, e);
+ /*
+ * Ideally, now we would send the received route to the rest of kernel code.
+ * But IPv6 ECMP routes are sent as a sequence of routes, so we postpone it
+ * and merge next hops until the end of the sequence.
+ */
+
+ if (!s->net)
+ {
+ /* Store the new route */
+ s->net = net;
+ s->attrs = ra;
+ s->proto = p;
+ s->new = new;
+ s->krt_src = src;
+ s->krt_type = i->rtm_type;
+ s->krt_proto = i->rtm_protocol;
+ s->krt_metric = priority;
+ }
else
- krt_got_route_async(p, e, new);
+ {
+ /* Merge next hops with the stored route */
+ rta *a = s->attrs;
+
+ if (a->dest != RTD_MULTIPATH)
+ {
+ a->dest = RTD_MULTIPATH;
+ a->nexthops = nl_alloc_mpnh(s, a->gw, a->iface, 0);
+ }
+
+ mpnh_insert(&a->nexthops, nl_alloc_mpnh(s, ra->gw, ra->iface, 0));
+ }
}
void
krt_do_scan(struct krt_proto *p UNUSED) /* CONFIG_ALL_TABLES_AT_ONCE => p is NULL */
{
struct nlmsghdr *h;
+ struct nl_parse_state s;
+
+ nl_parse_begin(&s, 1, krt_ecmp6(p));
nl_request_dump(BIRD_AF, RTM_GETROUTE);
while (h = nl_get_scan())
if (h->nlmsg_type == RTM_NEWROUTE || h->nlmsg_type == RTM_DELROUTE)
- nl_parse_route(h, 1);
+ nl_parse_route(&s, h);
else
log(L_DEBUG "nl_scan_fire: Unknown packet received (type=%d)", h->nlmsg_type);
+
+ nl_parse_end(&s);
}
/*
static void
nl_async_msg(struct nlmsghdr *h)
{
+ struct nl_parse_state s;
+
switch (h->nlmsg_type)
{
case RTM_NEWROUTE:
case RTM_DELROUTE:
DBG("KRT: Received async route notification (%d)\n", h->nlmsg_type);
- nl_parse_route(h, 0);
+ nl_parse_begin(&s, 0, 0);
+ nl_parse_route(&s, h);
+ nl_parse_end(&s);
break;
case RTM_NEWLINK:
case RTM_DELLINK:
void
krt_sys_io_init(void)
{
+ nl_linpool = lp_new(krt_pool, 4080);
HASH_INIT(nl_table_map, krt_pool, 6);
}
projects / thirdparty / bird.git / commitdiff
